The present invention relates to an absorbent article such as sanitary napkins, panty liners, incontinence pads, and disposable diapers for absorbing menstrual blood, vaginal discharges, urine and the like, and particularly to an absorbent article provided with a concavo-convex pattern on a permeable front surface sheet.
Front surface materials for absorbent articles, in which an appropriate emboss pattern is imparted in accordance with various objects such as suppressing a wet feeling by reducing a contact area with skin, or imparting texture to improve the feeling of contact with the skin have been commercialized. As materials of this kind, for example, the following Japanese Patent No. 4566059 and JP 2009-50538 A and the like can be cited.
In Japanese Patent No. 4566059, an absorbent article that includes a permeable front surface sheet, an impermeable or water-repellent back surface sheet, and an absorber located between the both sheets, and is provided with an intermediate sheet between the front surface sheet and the absorber is disclosed. The permeable front surface sheet includes a first layer that forms a skin contact surface, and a second layer that is adjacent to the first layer and disposed on the absorber side. The first layer is made of a fiber that has a fineness of 2.2 dtex or less and hydrophilicity that is not susceptible to decrease due to liquid permeation. The second layer is constituted of a fiber less fine than the constituent fiber of the first layer and contains a fiber of which hydrophilicity is not susceptible to decrease due to liquid permeation and a fiber of which hydrophilicity is susceptible to decrease due to the liquid permeation. The intermediate sheet includes a third layer facing the front surface sheet and a fourth layer that is adjacent to the third layer and facing the absorber. The constituent fiber of the third layer is less than the fineness of constituent fiber of the fourth layer. The fineness of the constituent fiber of the third layer is equal to or less than the fineness of the constituent fiber of the second layer. The constituent fiber of the fourth layer is finer than the constituent fiber of the second layer. (Of course, the finer the fiber the lower its dtex, and the less fine the fiber, the higher its dtex.) The constituent fibers of the third layer and fourth layer are a fiber of which hydrophilicity is not susceptible to decrease due to liquid permeation, and an entirety or a part of the constituent fiber of the third layer is formed of a solid crimped fiber.
Further, in JP 2009-50538 A, a sheet for an absorbent article in which a first sheet having an outside layer and an inside layer is intermittently joined to a second sheet at the inside layer is disclosed. In Japanese Patent No. 4566059 projected part protruding to the first sheet side formed between joining parts is connected to the sheet for an absorbent article, and a fiber that constitutes the outside layer of the first sheet is a fiber finer than the fiber that constitutes the inside layer.
In the absorbent article described in Japanese Patent No. 4566059, by imparting a gradient of fineness and a gradient of degree of durability of hydrophilicity to the front surface sheet and the intermediate sheet each formed into a two-layered structure, an excellent liquid return prevention property is imparted and the feeling on the skin is improved. However, the absorbent article is not formed into a structure that can maintain a concavo-convex shape of an emboss pattern when the emboss pattern is imparted to the front surface sheet.
In the same manner also in the sheet for absorbent article described in JP 2009-50538 A, it is disclosed to impart a gradient of fineness to an inside layer and an outside layer to impart comfortable touch feeling or the like on the skin. However, while a projected part collapses or deforms due to body pressure or the like to deteriorate feeling on the skin (“skin touch feeling”), there is no disclosure of a technology for maintaining the shape retention property of projected part or for making it difficult to deform.